Agilent Technologies Infiniium 90000 A Service Manual page 40

Chapter 3: Testing Performance
Analog Bandwidth - Maximum Frequency Check
Change the generator frequency to the maximum value for the model being tested as
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shown in the table below. It is not necessary to adjust the signal amplitude at this point
in the procedure.
Setting
Maximum Frequency
Scope Time Base Setting
Maximum Frequency
Scope Time Base Setting
Change the scope time base to the value for the model under test in the table above.
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Click here and enter time
base value from table
Measure the input power to the scope channel at the maximum frequency and convert
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this measurement to Volts RMS using the expression:
V = P
in meas
For example, if the power meter reading is 4.0 μW, then Vin = (4.0*10
Record the RMS voltage in the Analog Bandwidth - Maximum Frequency Check section of the
Performance Test Record (Vin @ Max Freq).
Press the Clear Display key on the scope and record the scope V rms reading in the
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Analog Bandwidth - Maximum Frequency Check section of the Performance Test
Record (Vout @ Max Freq).
Calculate the gain at the maximum frequency using the expression:
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Gain
Max Freq
For example, if (Vout @ Max Frequency) = 13.825 mV, (Vin @ Max Frequency) = 13.461 mV
and Gain @ 50MHz = 1.0023, then:
Gain
Max Freq
Record this value in the Calculated Gain @Max Freq column in the Analog Bandwidth - Maximum
Frequency Check section of the Performance Test Record. To pass this test, this value must be
greater than -3.0 dB.
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DSO/DSA90254A DSO/DSA90404A
2.5 GHz 4.0 GHz
100 ps/div 100 ps/div
DSO/DSA90804A DSO/DSA91204A
8.0 GHz 12.0 GHz
11.8 GHz at 5 mV/div
100 ps/div 100 ps/div
×
50Ω
(
V
out Max Freq
= 20 log ------------------------------------------------------------------------------
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13.825 mV 13.461 mV
= 20 log -------------------------------------------------------------
10
Model
DSO9/DSA0604A
6.0 GHz
100 ps/div
Model
DSO/DSA91304A
12.0 GHz,
11.8 GHz at
5 mV/div
100 ps/div
-6
* 50Ω)
) ⁄ (
V
in Max Freq
Gain
50 MHz
⁄
= 0.212 dB
1.0023
1/2
= 14.1 mVrms.
)